There seems to be a few different appdata and roaming folders. I have now found a multidoge folder in one of them. It contains a multidoge.wallet file of 1kb size. It is represented by a blank piece of paper and if I click on it, it says 'unable to find software for the selected file'.

Thank you so much for you help so far. What am I to do next? I want to make sure I don't cause any further problems.